Effects of aeration conditions on nitrogen removal performance and N2O emissions in a biofilm CANON reactor

IF 3.7 3区生物学 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Biochemical Engineering Journal Pub Date : 2025-03-13 DOI:10.1016/j.bej.2025.109724

Kunming Fu , Zirui Li , Huifang Wang , Hui Li , Xueying Su

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引用次数: 0

Abstract

The complete autotrophic nitrogen removal over nitrite (CANON) process offers significant nitrogen removal benefits, but N₂O emissions remain a concern. This study used a sequencing batch biofilm reactor (SBBR) to examine how different aeration conditions (aeration rates and strategies) affect N2O emissions during CANON. In the experiment, N₂O emissions were collected and calculated every 30 min, with nitrogen removal efficiency (NRE) maintained between 81 % and 92 %. The results showed that under continuous aeration conditions, as the aeration rate increased from 1 m³·(m³·h)⁻¹ to 8 m³·(m³·h)⁻¹, N₂O emissions significantly increased from 2.99 mg to 20.23 mg, and the emission proportion increased from 1.53 % to 9.74 %. Under intermittent aeration conditions, when the aeration rate was maintained at 8 m³·(m³·h)⁻¹ and the initial aerobic phase was shortened by 30 min, the system rapidly shifted from aerobic to anaerobic conditions, reducing N₂O emissions from 16.16 mg to 12.69 mg, with the emission proportion dropping from 7.94 % to 6.1 %. At this point, the concentration of NO₂^--N decreased from 27.77 mg·L⁻¹ to 18 mg·L⁻¹. The study suggests that the aeration rate influences N₂O generation by regulating dissolved oxygen (DO) concentration and NO₂^--N accumulation, and affects its release through the gas stripping effect. Appropriately shortening the duration of both the aerobic and anaerobic phases can effectively reduce N₂O emissions.

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来源期刊

Biochemical Engineering Journal 工程技术-工程：化工

CiteScore

7.10

自引率

5.10%

发文量

380

审稿时长

34 days

期刊介绍： The Biochemical Engineering Journal aims to promote progress in the crucial chemical engineering aspects of the development of biological processes associated with everything from raw materials preparation to product recovery relevant to industries as diverse as medical/healthcare, industrial biotechnology, and environmental biotechnology. The Journal welcomes full length original research papers, short communications, and review papers* in the following research fields: Biocatalysis (enzyme or microbial) and biotransformations, including immobilized biocatalyst preparation and kinetics Biosensors and Biodevices including biofabrication and novel fuel cell development Bioseparations including scale-up and protein refolding/renaturation Environmental Bioengineering including bioconversion, bioremediation, and microbial fuel cells Bioreactor Systems including characterization, optimization and scale-up Bioresources and Biorefinery Engineering including biomass conversion, biofuels, bioenergy, and optimization Industrial Biotechnology including specialty chemicals, platform chemicals and neutraceuticals Biomaterials and Tissue Engineering including bioartificial organs, cell encapsulation, and controlled release Cell Culture Engineering (plant, animal or insect cells) including viral vectors, monoclonal antibodies, recombinant proteins, vaccines, and secondary metabolites Cell Therapies and Stem Cells including pluripotent, mesenchymal and hematopoietic stem cells; immunotherapies; tissue-specific differentiation; and cryopreservation Metabolic Engineering, Systems and Synthetic Biology including OMICS, bioinformatics, in silico biology, and metabolic flux analysis Protein Engineering including enzyme engineering and directed evolution.